Fluid-pressure-controlled controlling mechanism



Oct. 25, 1932. o. c. SCHROEDER FLUID PRESSURE CONTROLLED CONTROLLING MECHANISM Original Filed March 12. 1927 2 Sheets-Sheet; l

Oct. 25, 1932. o. c. SCHROEDER 1,334,235

FLUID PRESSURE CONTROLLED CONTROLLING MECHANISM Original Filed March 12. 1927 2 Sheets-Sheet 2 h wfimmmu. a m w 2 0 "MA i// I 1 W Patented Oct. 25, 1932 UNITED- STATES OSCAR. c. scrmonnnn, or CHICAGO, rumors FLUID-PRESSURE-CONTROLLED CONTROLLING MECHANISM ori inal application filed larch 12,1927, Serial No. iugsa'nowratent n. 1,689,803; Divided an this applieation filed September 29, 1928." Serial No. 309,225,

2,1,0 simple and positively operating construction of controlling device ofthe type above referred to.

Another object is to provide a construction of such device which, whilesensitive in its operation, will not easilybecome out of order; and other objects as will be manifest from the following description.

The present application'is a division of my pending application for U. S.'Le.tters Patent Serial No, 174,7 82, filed March 1-2, 1927, upon which Letters Patent No. 1,689,803 were granted October 30,1928. 1

While my present invention may be used to advantage in many different situationsand in connection with many different kindsof apparatuses, I have devised it for use more particularly as a controlling element of automatic oil bmrner apparatus, such as forerrampic that disclosed in my said pending applica- I30 tion, and have therefore chosen to illustrate it in connection with burner control apparatus and more particularly the apparatus disclosed in my said pending application. I Referring to the accompanying draw mg I Figure 1 is a view in elevation, with certain parts sectioned of the lower portion of a furnace-structure equipped with an oil burner controlled by mechanism comprising, as one 9 of the controlling element-s thereof, a con-f trolling device embodying my invention. I

Figure 2 is a view in vertical sectional elevation of my improved controlling device showing it as associated with a switch controlled thereby and forming a part of the burner control apparatus, the parts shown heingint-he condition assumed by them when the switch illustrated is in closed condition; I and c i Figure 3, a similar View of the switch mechanism ofFig. 2showingit in open position.

Referring to Fig. 1,-the construction therein shown comprises a furnace containing a combustion chamber 5 in an opening 6 of the bottomwall Tof which a burner 8 is located. The burner shown, and in connection with which I have chosen to illustrate my invention is of the type disclosed in U. S. Letters Patent No. 1,505,607 granted to me on Angust'19, 1924; the forinof the burner has nothing todo with my present invention, description thereof appears to be unnecessary. It may be stated, however, that the burner is so constructed that the fuel issues therefrom at 9 throughout the periphery of the upper end of the'burner as represented at 10 when the motor 11 is running. 2

Located to one side of the burner proper 8 is. a pilot tube 12 adapted to be supplied with gas through a pipe 18 leading to a source of constant supply and controlled through the medium'of electrical controlling mechanism represented generally at 14,the tube 12 being so disposed that the flame produced by the igniting of the gas issuiIn therefrom will ignite the fuel-discharged from the burner 8,

there being associated with this pilot tube electrical igniter means comprising the two electrodes 15 and 16 which are spaced apart to present a spark gap intersecting the upper flow of the gas from the tube'12, these electrodes to'be supplied with current to produce sparking at this gap, by electrical mechanism represented generally at 17.

I At, the side ofthe burner 8 oppositethat at which the pilot tube 12 extends,is a switch device represented generally at18which is heat-controlled by mechanism represented generally'at 19 and embodying my invention, this switch device being provided as one of the controlling elements, for the burner controlling mechanism as clearly disclosed in my said pending application 'Ser. No. 174,782, which issued as Patent No. 1,689,803, this switch being operative responsive to changes in temperature condition at the burner 8. The switch 18 remains in normal, circuit.- closed, condition in case of failure of ignition of the fuel at the burner; is operated out of normal position following the ignition of the fuel at the burner, and returns to normal position following extinguishment of the flame at the burner.

The mechanism 19, according to the particular construction shown, comprises a hollow body 20 shown as of tubular form and closed except for an opening in its lower end at which it communicates with a pipe 21.

The side walls and top of the hollow body 20 are preferably constructed of relatively thin metal to permit of the quick heating of the contents of the member 20 by the subjection thereof to the heat of the flame produced by the oil in burning as it issues from the burner 8, and the cooling of such contents by the action of the atmosphere, upon the extinguishmentof theflame. V

The pipe 21 shown as carrying the member 20, is carried by, and communicates with, a chamber 22 in a bracket-head 23 supported on a rod 24 in turn carried by an arm 25 supported, on a post 26 forming, with other posts 27 and 28, legs for supporting the burner struc ture.

The chamber 22 contains a hollow member 29 having a depending, restricted, open-ended, cylindrical portion 30 opening at its lower end into the chamber 22 and at its'upper end into the space 31 provided by the member 29, the space 31 opening at its upper end to the atmosphere through an opening 32 in the side wall of the member 29 communicating with a passage 33 in the wall of the chamber 22. r

Reciprocable in the cylinder 30 is a piston 34 containing passages 35 and 36 extending lengthwise therethrough, the lower end of the passage 35 and the upper end of the passage 36 having valve seats for downwardly and upwardly opening check valves 37 b and 38, respectively, the seating-springs for which are represented at 39 and 40, respectively. The piston 34 is pivotally connected with the lower end of a link 41, the upper end of which extends through an opening 42 in a late 43 fitting down on the top of the memr 29, and pivotally connects with a lever 44 pivoted at one end, at 45, on a stud 46 rising from the plate 43. p

The other end of the lever 44 is provided with an arm 47 pivoted between its ends at 48 to the lever 44, the lower-end of the arm 47 carrying a roller 49 and its upper end connected with a coil spring 50 the other end of which connects with a lug 51 on the lever 44.

The roller-equipped end of the arm 47 co operates with the movable contact lever 52 of the switch 18, this contact lever being pivoted between its ends, as indicated at 53, to a stationary contact post 54, the contact lever 52 cooperating with a stationary contact 55 formingthe other element of the switch 18. V

The parts above described are so constructed and arranged, as shown, that when the piston 34 is in lowermost position, (Fig. 2), the switch 18 will be closed and when the piston 34 is raised to raise the lever 44 to the position shown in Fig. 3, the switch 18 will be open.

It may be here stated that in the relatively cold condition of the member 20, namely, when the burner is not operating, the switch device 18 assumes the position shown in Fig. 2 and the electrical circuit is closed at this point. Upon the application of heat to the member 20, as for example by thefiame created by the burner 8 in operating, the air in the member 20 becomes heated, thereupon expanding and producing a pressure within the chamber 22 causing the piston 34 to rise and rock the switch arm 52 controlled thereby to a position in whichthe circuit is broken at this point (Fig. 3).

The spring 40 is so tensioned that so long as the temperature of the member 20 rises or, after rising, remains substantially constant, the piston 34 will be in raised position and the circuit through the switch device 18 broken, excess pressure generated in the member 20 escaping therefrom into chamber 22 and thence past valve 38 and through port 32 and passage 33 to the atmosphere. In other Words, the construction referred to, by properly tensioning the spring 40 iinprisons, against escape, air up to a certain pressure sufiicient to hold the piston 34 raised and the switch device 18 in circuit open position, excess pressure generated in the receptacle 2O escaping to the atmosphere past the valve .38.

Upon the cooling of the receptacle 20 which results upon the extinguishment of the flame produced by the burner, this cooling effect eing augmented by providing a fine 56 shown in Fig. 1 for the upward circulation of air around the member 20, the air in the member 20 contracts with the result that the piston 34 lowers returning the switch device 18, connected therewith, to the circuit closed position represented in Fig. 2, and when the pressure of the air in the member 20 becomes reduced below a predetermined degree, determined by the tension of the spring 39, air from the atmosphere will be sucked into it by passing through passage 33, port 32, piston passage 35, and past valve 37.

It is preferred that the chamber 22 be charged with any suitable sealing oil which, by way of example, may exend to the level represented by the line 57, to the end that the piston 34 will operate smoothly and desirable clearance between the piston and the cylinder 30 provided without leakage of air past the piston 34.

WVhen oil is used in the device as stated the expansion of the air in member 20 produces a pressure upon the upper surface of the oil in chamber 22, the oil thussubjected to pres sure, acting from below against the piston 34 andcausing the latter to rise and rock the switch arm 52 controlled thereby to a position in which the circuit is broken (Fig. 3). Should pressure continue to be exerted in the member 20 after the piston 34, has reached the limit of'itsupward movement, oil beneath the piston will become forced past the check valve 38 and into the chamber 31. Should the pressure .in member '20 continue to increase to an extent sufiicient to force all of the oil. from chamber 22' below the lower edge ot cylinder 30', thus breaking the oil seal, the excess air pressure will'then pass from chamber 22' around the lower edge of cylinder 30 and escape through the oil and past the valve 381 and. through the oil thereabove to the atmosphere through the outlet 32. The device is so. constructed as shown that the volume of oil is such that it exceeds'the amount required for'efiecting the movement of the piston 34: from the position shown in Fig. 2 to its uppermost' position.

When the member 20 cools the oil displaced from: chamber 22 as stated will again flow into the chamber 22 and the continuing'reduction of temperature of the air in member 20 will lower the oil in cylinder 30 below its lower edgethereby permitting air from the atmosphere to pass around the lower edge of cylinder 30 and up through the body of oil in chamber 22; Manifestly the point in the operation of the apparatus at which air will pass beneath the cylinder 30 will depend upon the amount of oil used in the apparatus, the idea of prov ding for the operation as stated being to render the apparatus quickly responsive to changes in the pressure of the air in member 20.

By providing the oil of relatively small volume as stated the fit of the moving parts of the piston and cylinder mechanism, including the valves 37 and 38, may be muchl'ooser'than where the piston or valves are exposed directly to the operating air pressure. Furthermore, the excess air pressure gener ated in member 20 quickly vents past the valve 38 after thepiston 34- has performed its work by: movement in one direction and the oil in chamber 22 has lowered below the lower edge of the cylinderBO, and the air from the atmosphere quickly enters the device under the-suction action exerted thereon by the cooling of the member 20 after the piston has performed its work by movement in the opposite direction and the oil haslowered in the cylinder- 3O below the loweredge of the latter, whereby after completing its working stroke in one direction the mechanism is quickly conditioned for performing work by operation. in the opposite direction, such quick conditioning action being highly desirable, as for example. when. the device forms an element of an oil burner control mechanism.

By forming the chambers 22 and 31 as shown: and by preference, of larger diameter than the cylinder 30,. the oil in. the movement of the piston 34 in each direction is permitted to spread out and thus exertion of head pressure by the oil is greatly minimized.

It will be understood from thetoregoing that adevice constructed in, accordance with my inventionwill be positive and sensitive in operation, responding: quickly to changesof temperature at the burner.

The port 32. not only serves as an opening through which the air passes in the operation of the device. as stated, but also serves as a vent through which excess of. oil it charged into the apparatus, may escape.

While I have illustrated and-described a particularconstruction embodying my invention, and have shown it for use in a'particular' connection, I do not wish to be understood as intending to limit it to the particular form shown nor to its use inv apparatus of either the specific or general character stated.

What I claim as new, and desire to secure by Letters Patent, is:

1. In a device of the character described, the combination of an air chamber for subjection to heat, means operating responsive to the expansion and contraction of the air in said chamber and comprising a movable element and an oil seal subjected to the variations of air pressure in said air chamber and movable responsive thereto and in. such movements: controlling the position oi? said movable element, the structure containing inlet and outlet ports through which pressure in the continuing of expansion or the air in the chamber is relieved and suction in the continuing contraction of the air in said air chamber is relieved, respectively, and valves for said ports, said oil seal comprising such an amount of oil and the ports of the apparatus being so proportioned and arranged that following thev conclusion of the movement of said element in either direction the oil seal may become broken by' the air pressure against it and permit of the escape of air past said oil seala 2. In a device of the character described, the combination of an air chamber for sub.- jectionto heat, a cylinder in communication at one end: with said chamber, a piston in said cylinder containing passages in communication with said chamber and with the opposite end of said cylinder, oppositely closing check valves in said passages, means limiting the movement of said piston in opposite directions, and an oil seal for said piston subjected to the air pressure in said air chamber and operating to control the position of said piston responsive to the air pressure in. said chamber, said valves being immersed in said oil seal.

3'. In a device of the character described, the combination of an airchamber for subjection to heat, a cylinder in. communication with saidair chamber, a piston. insaid cylinder containing passages therethrough open ing to the atmosphere and in communication with said chamber, oppositely closing check valves controlling said passages, means limiting the movement of said piston in opposite directions, and an oil seal for said piston sub jected to the air pressure in said air chamber and operating to control the position of said piston responsive to the air pressure in said chamber, said valves being immersed in said oil seal.

4. In a device of the .character described, the combination of an air chamber for subjection to heat, means operating responsive to the expansion and contraction of the air insaid chamber and comprising a movable element and an oil seal subjected to the variations of air pressure in said air chamber and movable responsive thereto and in such movements controlling the position of said movable elementyt-he structure containing inlet and outlet ports, and check valves at said ports, the pressure in the continuing of expansion of the air in the chamber being relieved and suction in the continuing contraction of the air in said air chamber being relieved through said ports, respectively, said oil seal comprising such an amount of oil and the parts of the apparatus being so proportioned and arranged that following the conclusion of the movement of said element in either direction the oil seal may become broken by'the air pressure against it and per mits of the escape of air past said oil seal.

5. In a device of the character described, the combination of an air chamber for subjection to heat, means operating responsive to the expansion and contraction of the air in said chamber and comprising a movable elementand an oil seal subjected to the variationsof air pressure in said air chamber and movable responsive thereto and in such movements controlling the position of said movable element, the structure containing inlet and outlet ports, and check valves at said ports the pressure in the continuing of expansion of the air in the chamber being relieved and suction in the continuing contraction of the air in said air chamber being relieved through said ports, respectively, said valves being immersed in said oil seal, said oil seal comprising such an amount of oil and the parts of the apparatus being so proportioned and arranged that following the conclusion of the movement of said element in either direction the o l seal may become broken by the air pressure against it and permits of the escape of air past said oil seal.

.6. In a device of the character described, th combination of. an air chamber for subjection to heat, means operating responsive to the expansion and contraction of the air in said chamber and comprising a movable element and an oil seal subjected to the variations of air pressure in said air chamber and movable responsive thereto and in such movements controlling the position of said movable element, said movable element containing inlet and outlet ports, and valves at said ports, the pressure in the continuing of expansion of the air in the chamber being relieved and suction in the continuing contraction of the air in said air chamber being relieved through said ports, respectively, said oil seal comprising such an amount of oil and the parts of the apparatus being so proportioned and arranged that following the conclusion of the movement of said element in either direction the oil seal may become broken by the air pressure against it and permits of the escape of air past said oil seal.

7 In a device of the character described, the combination of an air chamber for subjection to heat, means operating responsive to the expansion and contraction of the air in said chamber and comprising a movable ele ment and an oil seal subjected to the variations of air pressure in said air chamber and movable responsive thereto and in such movements controlling the position of said movable elcment. said movable element containing inlet and outlet ports, and check valves for said ports, thepressure in the continuing of expansion of the air in the chamber being relieved and suction in the continuing. contraction of the air in said air chamber being relieved through said ports, respectively, said oil seal comprising such an amount of oil and the parts of the apparatus being so proportioned and. arranged that following the conciusion of the movement of said element in either direction the oil seal may become broken by the air pressure against it and permits of the escape of air past said oil seal.

8. In a device of the character set forth, the combination of an air chamber for subjection to heat, an oil well in communication with said chamber, a cylinder extending into said well and opening into the latter below the level of the oil. in said well, a piston in said cylinder, the structure containing inlet and outlet ports, and valves at said ports, the pressure in the continuing of expansion of the air in said chamber being relieved and suction in the continuing contraction of the air in aid chamber being relieved through said ports, respectively.

9. In a device of the character set forth, the combination of an air chamber for subjection to heat, an oil well in communication with said chamber, a cylinder extending into said well and opening into the latter, below the level. of the oil in said well, a piston in said cylinder, the structure containing inlet and outletports, and check valves at said portions, pressure in the continuing of expansion of the air in said chamber being relieved and uction in the continuing conthe traction of the air in said chamber being relieved through said ports, respectively.

10. In a device of the character set forth,

the combination of an air chamber for subinder, the structure containing inlet and outlet ports, and valves at said ports, the pressure in the continuing of expansion of the air in said chamber being relieved and suction in the continuing contraction of the air in said chamber being relieved through said ports, respectively.

11. In a device of the character set forth, the combination of an air chamber for sub jection to heat, a cylinder in communication at one end with said chamber and having an expanded upper portion, a piston in said cylinder, an oil seal for said piston subjected to the air pressure in said air chamber and operating to control the position of saidpiston responsive to the air pressure in said chamber, the structure containing inlet and outlet ports and valves atsaid ports, the pressure in the continuing of expansion of the air in the chamber being relieved and suc tion in the continuing contraction of the air in said chamber being relieved through said ports, respectively.

12. In a device of the character set forth, the combination of a chamber for subjection to heat, an oil well in communication with said chamber, a. cylinder extending into said well and opening into the latter below the level of the oil therein, said cylinder having an expanded upper portion, a piston in said cylinder, said oil well providing an oil seal for said piston subjected to the air pressure in said air chamber and operating to control the position of said piston responsive to the air pressure insaid chamber, the structure.

containing inlet and outlet ports, and valves at said ports, the pressure in the continuing expansion of the air in said chamber being relieved and suction in the continuing contraction of the air in said chamber being relieved through said ports, respectively.

13. In a device of the character described, the combination of an air chamber for subjection to heat, means operating responsive tothe expansion and contraction of the air in said chamber and comprising a movable element and an oil seal subjected to the variations of air pressure in said air chamber and movable responsive thereto and in such movements controlling the position of said movable element, the structure containing inlet and outlet ports, and check valves for said ports, the pressure in the continuing of expansion of the air in the chamber being relieved and suction in the continuing contraction of the air in said chamber being relieved, respectively, through said ports,

and means limiting the movement of said element in opposite directions, said oil seal comprising such an amount of oil and the parts of the apparatus being so proportioned and arranged that following the conclusion of the movement of said element in either direction the oil seal may become broken by the air pressure against it and permits the escape of air past said oil seal.

14. In a device of the character described, the combination of an air chamber for subjection to heat, means operating responsive to the expansion and contraction of the air in said chamber and comprising a movable element and an oil seal subjected to the variations of air pressure in said air chamber and movable responsive thereto and in such movements controlling the position of said movable element, the structure containing inlet and outlet ports through which pressure in the continuing of expansion of the air in the chamber is relieved and suction in the con-- tinuing contraction of the air in said air chamber is relieved, respectively, and valves for said ports, said valves being immersed in said oil seal, said oil seal comprising such an amount of oil and the parts of the apparatus being so proportioned and arranged that following the conclusion of the movement of c said element in either direction the oil seal may become broken by the air pressure against it and permit of the escape of air past said oil seal.

OSCAR c. sonaonnnn. 

